If SPA is provisioned via Storage Account Blob (e.g. with Static Website feature) then it is higly recommended to setup a CDN for following purposes:
Further the CDN is used for Custom Domain setup, SSL and additional performance improvement (and cost optimization for highly used applications).
A CDN setup consists of following resources:
https://stackoverflow.com/questions/58914446/azure-cdn-microsoft-standard-rewrite-url-angular